Medtronic Inc., Memphis, Tennessee.
Medtronic Inc., Minneapolis, Minnesota.
J Biomed Mater Res B Appl Biomater. 2018 Nov;106(8):2858-2868. doi: 10.1002/jbm.b.34067. Epub 2018 Jan 10.
Posterior spinal fusion implants include number of interconnecting components, which are subjected to micromotion under physiological loading conditions inducing a potential for fretting corrosion. There is very little known about the fretting corrosion in these devices in terms of the minimum angular displacement (threshold) necessary to induce fretting corrosion or the amount of fretting corrosion that can arise during the life of the implant. Therefore, the first goal was to evaluate the threshold fretting corrosion in three anatomical orientations and second the long-term fretting corrosion for the three different material types of spinal implants under physiological loading conditions. In threshold test, axial rotation exhibited highest changes in open circuit potential (V in mV) and induced fretting currents (I in µA) for cobalt chrome (ΔV : 24.71 ± 5.53; ΔI : 4.03 ± 0.51) and stainless steel (ΔV : 28.21 ± 6.97; ΔI : 2.98 ± 0.42) constructs whereas it was flexion-extension for titanium constructs (ΔV : 4.51 ± 2.48; ΔI : 0.38 ± 0.12). Long-term test indicated that the titanium (V :101 ± 0.06; I : 0.07 ± 0.02) and cobalt chrome (V : 140.67 ± 0.04; I : 0.12 ± 0.05) constructs were more resistant to the fretting corrosion compared to stainless steel (V : -135.33 ± 0.31; I : 2.63 ± 1.06). © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2858-2868, 2018.
脊柱后路融合植入物包括多个相互连接的部件，这些部件在生理负荷条件下会发生微动，从而产生微动腐蚀的可能性。在这些装置中，关于引起微动腐蚀所需的最小角位移（阈值）或在植入物寿命期间可能出现的微动腐蚀量，人们知之甚少。因此，第一个目标是评估三种解剖方向的阈值微动腐蚀，其次是在生理负荷条件下，三种不同材料类型的脊柱植入物的长期微动腐蚀。在阈值试验中，钴铬（ΔV：24.71±5.53；ΔI：4.03±0.51）和不锈钢（ΔV：28.21±6.97；ΔI：2.98±0.42）结构的轴向旋转表现出最大的开路电位（V in mV）和诱导微动电流（I in μA）变化，而钛结构则是弯曲-伸展（ΔV：4.51±2.48；ΔI：0.38±0.12）。长期试验表明，与不锈钢（V：-135.33±0.31；I：2.63±1.06）相比，钛（V：101±0.06；I：0.07±0.02）和钴铬（V：140.67±0.04；I：0.12±0.05）结构更能抵抗微动腐蚀。©2018Wiley Periodicals，Inc. J Biomed Mater Res Part B：Appl Biomater，106B：2858-2868，2018。
